Storage Temperature and Atmosphere Alleviates Chilling Injury of Marula (Sclerocarya birrea subspecies caffra) Fruit

Abstract

Low temperature storage is the most effective technology for keeping quality and extending the postharvest life of fresh horticultural produce. However, horticultural produce of tropical and subtropical in origin such as marula fruit are susceptible to chilling injury (CI) when stored at temperatures below their critical minimum temperatures. Therefore, low temperature storage alone is not ideal for produce of tropical and subtropical in origin. The aim of this research was to elucidate the influence of modified atmosphere packaging (MAP) on CI of marula fruits. Storage temperature below 12ºC significantly (P < 0.05) increased CI incidence and severity, and proline content of marula fruit. Marula fruit in MAP had significantly (P < 0.05) lower electrolyte leakage than fruit stored in Air. The results further showed that marula fruit stored at 12?C in MAP had significantly longer shelf-life of 21 days than fruits in Air stored at various temperatures which had a shorter shelf life. It was concluded that marula fruits be stored in MAP at 12°C plus 90-95% RH to alleviate CI incidence and severity and maintain fruit quality and extend shelf-life. Keywords: Marula Fruit; MAP; Chilling Injury; Proline Content; Electrolyte Leakage